From: Christoph Hellwig <hch@lst.de>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Larry Finger <Larry.Finger@lwfinger.net>,
Aaro Koskinen <aaro.koskinen@iki.fi>,
Christoph Hellwig <hch@lst.de>,
Christian Zigotzky <chzigotzky@xenosoft.de>,
Michael Ellerman <mpe@ellerman.id.au>,
linuxppc-dev@lists.ozlabs.org, linux-wireless@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [BISECTED REGRESSION] b43legacy broken on G4 PowerBook
Date: Tue, 11 Jun 2019 08:08:16 +0200 [thread overview]
Message-ID: <20190611060816.GA20158@lst.de> (raw)
In-Reply-To: <c91ccbddd6a58dbee5705f10ed1d98fb44bd8f8d.camel@kernel.crashing.org>
On Tue, Jun 11, 2019 at 03:56:33PM +1000, Benjamin Herrenschmidt wrote:
> The reason I think it sort-of-mostly-worked is that to get more than
> 1GB of RAM, those machines use CONFIG_HIGHMEM. And *most* network
> buffers aren't allocated in Highmem.... so you got lucky.
>
> That said, there is such as thing as no-copy send on network, so I
> wouldn't be surprised if some things would still have failed, just not
> frequent enough for you to notice.
Unless NETIF_F_HIGHDMA is set on a netdev, the core networkign code
will bounce buffer highmem pages for the driver under all circumstances.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>,
linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
Christian Zigotzky <chzigotzky@xenosoft.de>,
linuxppc-dev@lists.ozlabs.org, Christoph Hellwig <hch@lst.de>,
Larry Finger <Larry.Finger@lwfinger.net>
Subject: Re: [BISECTED REGRESSION] b43legacy broken on G4 PowerBook
Date: Tue, 11 Jun 2019 08:08:16 +0200 [thread overview]
Message-ID: <20190611060816.GA20158@lst.de> (raw)
In-Reply-To: <c91ccbddd6a58dbee5705f10ed1d98fb44bd8f8d.camel@kernel.crashing.org>
On Tue, Jun 11, 2019 at 03:56:33PM +1000, Benjamin Herrenschmidt wrote:
> The reason I think it sort-of-mostly-worked is that to get more than
> 1GB of RAM, those machines use CONFIG_HIGHMEM. And *most* network
> buffers aren't allocated in Highmem.... so you got lucky.
>
> That said, there is such as thing as no-copy send on network, so I
> wouldn't be surprised if some things would still have failed, just not
> frequent enough for you to notice.
Unless NETIF_F_HIGHDMA is set on a netdev, the core networkign code
will bounce buffer highmem pages for the driver under all circumstances.
next prev parent reply other threads:[~2019-06-11 6:08 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-05 22:50 [BISECTED REGRESSION] b43legacy broken on G4 PowerBook Aaro Koskinen
2019-06-05 22:50 ` Aaro Koskinen
2019-06-06 0:54 ` Benjamin Herrenschmidt
2019-06-06 0:54 ` Benjamin Herrenschmidt
2019-06-06 9:31 ` Aaro Koskinen
2019-06-06 9:31 ` Aaro Koskinen
2019-06-06 10:56 ` Benjamin Herrenschmidt
2019-06-06 10:56 ` Benjamin Herrenschmidt
2019-06-06 10:57 ` Benjamin Herrenschmidt
2019-06-06 10:57 ` Benjamin Herrenschmidt
2019-06-06 11:43 ` Christoph Hellwig
2019-06-06 11:43 ` Christoph Hellwig
2019-06-06 19:26 ` Larry Finger
2019-06-06 19:26 ` Larry Finger
2019-06-06 20:11 ` Larry Finger
2019-06-06 20:11 ` Larry Finger
2019-06-06 3:06 ` Larry Finger
2019-06-06 3:06 ` Larry Finger
2019-06-06 6:40 ` Christoph Hellwig
2019-06-06 6:40 ` Christoph Hellwig
2019-06-07 17:25 ` Larry Finger
2019-06-07 17:25 ` Larry Finger
2019-06-07 17:29 ` Christoph Hellwig
2019-06-07 17:29 ` Christoph Hellwig
2019-06-07 18:50 ` Larry Finger
2019-06-07 18:50 ` Larry Finger
2019-06-08 21:52 ` Larry Finger
2019-06-08 21:52 ` Larry Finger
2019-06-10 8:18 ` Christoph Hellwig
2019-06-10 8:18 ` Christoph Hellwig
2019-06-10 16:09 ` Larry Finger
2019-06-10 16:09 ` Larry Finger
2019-06-11 6:05 ` Christoph Hellwig
2019-06-11 6:05 ` Christoph Hellwig
2019-06-11 22:20 ` Larry Finger
2019-06-11 22:20 ` Larry Finger
2019-06-11 22:46 ` Aaro Koskinen
2019-06-11 22:46 ` Aaro Koskinen
2019-06-12 1:57 ` Larry Finger
2019-06-12 1:57 ` Larry Finger
2019-06-11 22:46 ` Benjamin Herrenschmidt
2019-06-11 22:46 ` Benjamin Herrenschmidt
2019-06-12 1:52 ` Larry Finger
2019-06-12 1:52 ` Larry Finger
2019-06-12 3:32 ` Benjamin Herrenschmidt
2019-06-12 3:32 ` Benjamin Herrenschmidt
2019-06-12 6:55 ` Christoph Hellwig
2019-06-12 6:55 ` Christoph Hellwig
2019-06-12 19:41 ` Larry Finger
2019-06-12 19:41 ` Larry Finger
2019-06-12 21:59 ` Benjamin Herrenschmidt
2019-06-12 21:59 ` Benjamin Herrenschmidt
2019-06-13 7:29 ` Christoph Hellwig
2019-06-13 7:29 ` Christoph Hellwig
2019-06-11 17:48 ` Andreas Schwab
2019-06-11 17:48 ` Andreas Schwab
2019-06-08 4:21 ` Benjamin Herrenschmidt
2019-06-08 4:21 ` Benjamin Herrenschmidt
2019-06-08 7:23 ` Christoph Hellwig
2019-06-08 7:23 ` Christoph Hellwig
2019-06-10 18:44 ` Larry Finger
2019-06-10 18:44 ` Larry Finger
2019-06-11 5:56 ` Benjamin Herrenschmidt
2019-06-11 5:56 ` Benjamin Herrenschmidt
2019-06-11 6:08 ` Christoph Hellwig [this message]
2019-06-11 6:08 ` Christoph Hellwig
2019-06-11 6:58 ` Benjamin Herrenschmidt
2019-06-11 6:58 ` Benjamin Herrenschmidt
2019-06-11 6:59 ` Benjamin Herrenschmidt
2019-06-11 6:59 ` Benjamin Herrenschmidt
2019-06-11 7:54 ` Christoph Hellwig
2019-06-11 7:54 ` Christoph Hellwig
2019-06-11 9:04 ` Benjamin Herrenschmidt
2019-06-11 9:04 ` Benjamin Herrenschmidt
2019-06-11 7:53 ` Christoph Hellwig
2019-06-11 7:53 ` Christoph Hellwig
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